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siRNA Electroporation to Modulate Autophagy in Herpes Simplex Virus Type 1-Infected Monocyte-Derived Dendritic Cells
Published on: October 28, 2019
EcPSMB9 contributes to antiviral responses through autophagy-related and MHC I-associated processes and associates
Jinpeng Chen1, Xin He1, Shen Li1
1College of Marine Sciences, South China Agricultural University, Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China.
Abstract:
Proteasome subunit beta type-9 (PSMB9) is a catalytic subunit of the immunoproteasome and plays an essential role in antigen processing and MHC class I (MHC I)-restricted cellular immunity in mammals. However, the role of PSMB9 in fish antiviral immunity remains poorly understood. In this study, we cloned and characterized the PSMB9 homologue from orange-spotted grouper (Epinephelus coioides), designated EcPSMB9, and investigated its potential role in host defence against Singapore grouper iridovirus (SGIV) and red-spotted grouper nervous necrosis virus (RGNNV). EcPSMB9 overexpression was consistently associated with reduced viral burden during both SGIV and RGNNV infection. In parallel, EcPSMB9 overexpression was accompanied by decreased GFP-LC3 puncta formation, lower LC3-II protein levels, and reduced expression of ATG5, ATG12, and ATG16, together with enhanced MHC I-associated and interferon-associated transcriptional activity, suggesting that EcPSMB9 may participate in antiviral defence through coordinated changes in proteostasis-related and antigen presentation-associated processes. Notably, structural modeling and co-immunoprecipitation analyses revealed an association between EcPSMB9 and the core immunoproteasome subunit EcPSMB8. Together, these findings suggest that EcPSMB9 is a conserved immunoproteasome subunit linked to antiviral responses in grouper and indicate that immunoproteasome subunit cooperation may be relevant to teleost antiviral immunity.
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